Grinding and sharpening machine.



H. D. NIGHOLLS. GRINDING AKD SHARPENING MACHINE- APPLICATION TILED MAY 1, 1907. 969,649. Patented Sept. e, 1910.

3 SEBETSSHEET 1.

1n: NORRIS FLTERS ca. WASHINGYON, D. c.

11-. D. NIGHOLLS. GRINDING AND SHARPENING MACHINE. I

' APPLICATION FILED MAY 1, 1907. I I 969,649. Patented Sept. 6,1910.

3 SHEETS-SHEET 2.

H. D. NIGHOLLS. GRINDING AND SHARPENING MACHINE.

APPLIOATION FILED MAY 1, 1907. 969,649. Patented Sept. 6, 1910. 3 SHEETS-SHEET 3.

E uoxms Psi-215cm. wmunmun, n. c.

UNITED STATES PATENT oEEroE.

Specification of Letters Patent. Application filed May 1, 1907.

969,649. Patented Sept. 6, 1910.

Serial No. 371,244.

['0 all whom it may concern: Be it known that I, HENRY D. N ICHOLLS, a cltizen of the United States, and a resident I! wheel around the entire of Philadelphia, Pennsylvania, have in-] l edge of the saw, the cranked shaft at right angles to the face of the saw, to a position on the opposite side of the same with the cranked shaft in the same relative position. In addition to this movement imparted to the emery wheel carrier, the latter is also moved laterally by reciprocative movement imparted to the shaft 15 as the emery wheel is revolving so that the saw teeth are engaged from end to end of the same, and when finished will have a rounded face or edge that is beveled from the point to the heel of the tooth, on a line vented certain Improvements in Grinding and Sharpening Machines, of which the following is a specification.

My invention relates to grinding or sharpening machines, and consists of an improved apparatus of teeth of metal cutting saws or milling tools.

fully shown in the accompanying drawings, in which:

Figure l, is a front elevation of a matangent to the arc ofa circle struck from the chine embodying my invention; Fig. 2, is center of the saw, the emery wheel being a plan view of the same; Fig. 3, is a side eleset to one side of a vertical line passing vation; Figs. 4, 5, through the to effect the of the teeth.

The shaft 15 is mounted in bearings 16 in which it may be reciprocated, and carries a pinion 17 in operative engagement with a rack bar 18, suitably guided and driven by center of rotation of the saw, beveling as well as the rounding The machine forming the subject of my invention consists of a bed or base plate 1, supported by a suitable framework 2, upon which is mounted an adjustable carrier 3, upon which the rotary saw or cutter 5 is mounted, (the latter being shown by dotted oscillated back and lines.) r ger 6, operated by suitable wheel carried by the present instance being carried driven spindle 8, is employed to move the rocking or reciprocation and reduce said saw or cutter the distance of one tooth at a edge from one having time. This structure is commonly emhaving a semicircular contour. The crank ployed in connection with saw sharpening shaft 15 has an arm 22 at its end upon which or grinding machines and forms no part of counterbalance weights 23 are mounted. my invention. The outer edge or surface The frame 13 supporting the shaft or of each tooth 9 of the saw or cuttenis to be spindle 11 011 which is provided for by means i a screw, operated by a hand wheel 25. I This screw is suitably anchored in the poredge of each tooth is reduced and gradually 1 tion 14 of the cranked assumes a rounded contour. The adjustable 1 frame 13 supporting the bearings 12 of the rying the emery wheel. By this means the emery wheel is carried by the cranked end emery wheel may be adjusted from and toward the work. e center line of the j ourleys 27,

and means are preferably provided to limit the downward movement of the emery wheel so that it will finish the teeth uniformly. This stop member should be adjustable so that wear of the emery wheel may be compensated for.

To drive the emery wheel, its shaft 11 is provided with a pulley 27, and pulleys 28 and 29 are carried by a frame 30. To drive these pulleys a band or cord 31 is employed which passes from a driven pulley 32 mounted on the driving shaft- 21 around said pul- 28 and 29; an idler pulley 34 being employed, carried by an arm 35 loosely mounted on the shaft 21, so as to take up any slack in the band or cord 31. The shaft 21 is driven from any suit-able source of power.

The shaft 15 is reciprocable in its bearings during the rocking or oscillating movement, and the reciprocation is accomplished by the following means: Mounted in suitable hearings on the bed plate of the machine and disposed at right angles to the shaft 15, is a shaft 42 carrying a face plate 43 having a pin 44 in engagement with a vertically slotted member 45 carried by said shaft .15. As the shaft 42 is rotated, the face plate is rotated with it and the pin engaging the walls of the slotmoves said shaft 15 back and forth in its bearings. By this means the emery wheel is traversed back and forth along each tooth simultaneously with its rotation, and as it is carried back and forth by the rocking or oscillation of the shaft 15. The rocking or oscillation of the shaft 15 is caused by the engagement of the reciprocating rack bar 18 with the pinion 17 mounted on said shaft. The cam plate 19 carried by the shaft has a groove 49 in its face. The center of this cam plate is provided with a pin 46, and the bar 17 is slotted at 47 to engage this pin and is provided with an anti-friction roller 48 in engagement with the cam slot or groove 49. As the cam plate rotates, the rack bar 18 is drawn back and forth and its toothed end being in engage ment with the pinion 17, it rocks or oscillates the shaft 15, the connection and extent of movement being of such character as to prevent rotation of said shaft. The cam groove is provided with an offset portion 49 which serves to stop the rocking or oscillating movement of the cranked shaft for a. length of time sufficient to permit the feeding of the saw one tooth at a time for the engagement of the emery wheel upon a fresh part. The saw is fed continuously one tooth for every revolution of the cam 19 and the grinding action takes place very gradually, such saw making probably twenty or more revolutions before the teeth are rounded to the extent desired. When finished the teeth will also be beveled from point to heel as clearly shown in Figs. 4, 5, 6 and 7, of the drawings, a condition due to the ofisetting sharpening wheel the squared l to be rounded being of the center of the saw with respect to the position of the emery wheel.

The machine just described is one designed for rounding each tooth of a circular milling saw or cutter, and such teeth are gradually rounded by rotating such saw continuously in such position as to be engaged by the emery or other sharpening wheel. There are, however, other types of milling saws or cutters, notably one in which every other tooth is left plain or square so that in making a cut by the use of a saw of this character, the rounded portion of the kerf made by the rounded teeth will be cleaned out by the square cutting edges or corners of the square teeth. For the purpose, therefore, of rounding the alternate teeth of such a saw as this, I provide the cam mechanism clearly shown in Fig. 8, in which means are provided for bringing the emery wheel frame into a vertical position so that the feeding mechanism designed to move the saw by engagement with the teeth will be able to effect such movement two teeth at a time, with the emery or other in such position with respect to the saw that it will not act upon edge. This movement may only take place when the emery wheel is directly above the teeth, for in such position there will always be sufficient clearance bet-ween such cutter and the teeth it is not desired to round. To permit this action, I employ a cam 19, as shown in Fig. 8, which may be mounted on the shaft 21, and having a cam groove 45, which is engaged by a roller 48, mounted on the rack bar 18, which is guided in a manner similar to the rack bar 18, and engages the pinion 17 to impart movement thereto. This rack bar is provided with a slot 47 which is engaged by the pin 46 on the end of the shaft 21. The groove 45 of the cam 19 is so proportioned and disposed as to operate the emery wheel in order to bring the latter in engagement with the saw teeth and effect the rounding of the same, and is further provided with a portion 50 which will cause such frame and the rocker or crank shaft to pause in a vertical position for a length of time sufficient to move the saw the distance of two teeth so that the emery wheel may always engage the proper teeth to be rounded, the alternate teeth being left in the original rectangular condition. When this form of cam mechanism is employed, the pusher arm and the eccentric for operating the same will be arranged to move two teeth instead of one, the eccentric being proportionately larger to ef fect this movement. In all other respects, this cam will operate the machine exactly the same as the cam shown in Figs. 1, 2 and 3, and the operation of grinding or sharpening the teeth is the same; the alternate teeth gradually reduced from their square shape to semi-circular shape, ing Wheel to engage the work in the are of such reduction or t e saw is rotated.

c aim:

Wheel mounted for rotation and arranged to engage said Wor a cranked shaft supporting said grinding Wheel, a pinion carried by said shaft, a racked ber in operative 2. n a grinding or sharpening machine, the combination of means for supporting mounted for rocranked shaft and having a portion in operative engagement With the groove of the cam whereby it may be actuated by the latter to give said cranked shaft a rocking or oscillating movement and cause the grindg I shaft grinding being made as I a circle struck from the center of oscillation.

the Work, a grinding Wheel mounted for r tation, a support for said wheel, a cranked carrying said support, a pinion carrled at one end of said shaft, a driving shaft, a grooved cam plate carried by said driving shaft, a racked member suitably on the cranked shaft and having a portion in operative engagement With the groove of the cam whereby it may be actuated by the latter to give said cranked shaft a rocking or oscillating movement and cause the grinding Wheel to engage the Work in the arc of a circle struck from HENRY D. N IOHOLLS.

Witnesses:

MURRAY C. BoYER, Jos. H. KLEIN. 

